Republican party leaders scrambled to persuade Donald Trump to abandon the divisive tactics that have triggered sinking poll numbers and low morale.
Party chairman Reince Priebus appealed to Mr Trump’s adult children to help amid new signs of a campaign in trouble.
Mr Trump’s operation has been beset by internal discord, including growing concern about election preparedness and a lack of support from Republican leaders.
One source said Mr Trump privately blames his own staff for failing to stop the backlash from his own party after he criticised an American Muslim family whose son, a US Army captain, was killed in Iraq.
The inner tension comes as Mr Priebus and other high-profile Trump allies consider whether to confront the candidate directly to encourage a new approach following a series of startling statements.
In the middle of the uproar over his continued criticism of the Khan family, Mr Trump infuriated Mr Priebus and other party leaders by refusing to endorse Republican House Speaker Paul Ryan’s re-election.
Mr Trump on Wednesday dismissed suggestions that the frustration was hurting his campaign.
“We’ve never been this united,” he said during a campaign stop in battleground Florida.
